US2206151A

US2206151A - Process of sulphurizing oils

Info

Publication number: US2206151A
Application number: US59311A
Authority: US
Inventors: Harry T Bennett
Original assignee: Mid Continent Petroleum Corp
Current assignee: Mid Continent Petroleum Corp
Priority date: 1936-01-15
Filing date: 1936-01-15
Publication date: 1940-07-02
Anticipated expiration: 1957-07-02

Description

Patented July 1940 UNITED STATES PATENT OFFICE" PROCESS OF SULPHUBIZING OILS Harry T. Bennett, Tulsa, Okla assig'nor to Mid- Continent Petroleum Corporation, Tulsa, Okla., a corporation of Delaware No Drawing.

1 Claim.

oils have been used to a considerable extent in the manufacture of extreme pressure lubricants, and cutting oils. These sulphurized oils when blended with a mineral lubricating oil impart to the blended oil the property of lubricating at extremely high pressures. It is to be understood that high temperatures result in the thickening of the oils, and that prolonged heating even at lower temperatures will also thicken the oil. The present invention eliminates such thickening and produces a sulphurized oil in the fluid state required for extreme pressure lubricants.

Heretofore, the cost of preparing sulphurized oils has been objectionable, as it has required relativelylong periods of time at high treating temperatures to combine sulphur with oils. Moreover, during these relatively long processes at high temperatures, hydrogen sulphide is evolved and other sulphur products are formed during the reaction.

As an illustration of the conventional processes employed in sulphurizing oils prior to my invention, I will refer to a treatment wherein lard oil is sulphurized. The lard oil is heated to a temperature of 325 F. with slow agitation in a suitable container. Sulphur is then added to the lard oil at the rate of 20 parts by weight of sulphur to parts of lard oil, and the resultant mixture stirred at 325 F. during the course of four to five hours, or until the sulphur is combined with the oil. If it is desired to produce a product that will not corrode copper, the resultant sulphurized mixture is then cooked at 325 F. for an additional hour or more until a bright highly polished copper strip exposed to the mixture shows no corrosion. When it is .unnecessary to produce a product that will not corrode copper, the final cooking step may be omitted.

In commercial practice, there would be a very substantial reduction in the cost of sulphurizing oils if the total reacting time of the old processes could be reduced, or if lower treating temperatures could be employed, or if both the time and temperatures were reduced.

I have found that certain compounds, which I term sulphur-combining agents, when added in small quantities to the oil to be sulphurized reduced the reaction time, or permitted the reaction to take place at a lower temperature.

Application January 15, 1936, Serial No. 59,311

In carrying out my process,'the sulphur-combining agent is usually added to the oil at the same time as the sulphur, but may be added just before or after the addition of the sulphur without any loss in efficiency. The resultant mixture 5 is agitated at the desired reacting temperature until thesulphur is combined with the oil. If it is desired to produce a product that will not corrode copper, the sulphurized mixture is then cooked until a polished copper strip immersed into the mixture shows no corrosion. Any sulphur-combining agent which will pro-' mote the desired reaction between the oil and sulphur may be employed in carrying out my process, 'and the following list is illustrative of various compounds which I have found satisfactory. Aromatic amino compounds:

Aniline Diphenyl guanidine 'I'riphenyl guanidine Methylene-p-toluidine Diorthotolyl guanidine Ethylidene aniline Heptaldehyde aniline Formanilide Butylaldehyde aniline Nitrosodimethylaniline Aromatic sulphur compounds:

Mercaptobenzthiazole Aromatic amino sulphur compounds:

Diphenyl thiourea Diethyl ammonium dlethyl dithiocarbamate' v the time of reaction as compared to an example wherein no sulphur-combining agent was employed.

Table I Qualntgty of su urcom ining gggg Sulphur-combining agent used agent, time grams per hours 100 grams lard oil None None 4 10 2 Hexamethylenetetramine 10 2% Tetramethyl thiuram disul hide 2 1% Diethyl ammonium diet yl dithiocarbamate 2 1% In each of the examples given in Table I, the same proportions'of lard oil and sulphur were employed, and in each instance the resultant products were stirred at 325 F. during the indicated reacting time.

As a further illustration of the efiect of sul- 1 phur-combining agents on the time of reaction, I have compared in the following Table II the use of different quantities of diorthotolyl thiourea with an example where no sulphur-combining agent was employed.

Table II Quantity of Tctal cr i r r i b i i i i n Reactin reacting Sulphur-combining agent em g te g and used fig mpet' cooking glslams per ature time,

grams lard oil hours F. None None 325 6% Diorthotolyl thiourea l l. 325 3 D0 0. 25 325 4% The sulphur-combining agents will also permit a reduction in reaction temperatures, as shown by the following Table III.

Table III Quantity of sulphur Total re- Sulphur-combining agent g g ag? acting used g n a time grams per reaction hour's 100 grams lard Oil F. None None 325 4 Do None 285 5% Diorthotolyl tbiourea 2 285 4 In each of the foregoing tables I have referred to lard oil as the material treated. However, it is not my intention to limit this invention to a. specific oil as the various animal, vegetable and mineral oils may be sulphurized in accordance with my process.

As an illustration of the use of a sulphurcombining agent in sulphurizing a mineral oil, I will refer to the treatment of a S. A. E. 30 motor oil, with diorthotolyl thiourea. One hundred parts by weight of the oil were heated with 20 parts of sulphur and two parts of diorthotolyl thiourea and stirred at a temperature of 325 F. for eight hours. After this period of time the mixture showed no uncombined sulphur.

As a comparison, the foregoing process employing the same materials except for the sulphurcombining agent, was carried out for thirteen hours and even after this long heating period uncombined or free sulphur was present in the mixture.

While I have given numerous specific examples of my process to illustrate the invention, it is understood that changes and modifications may be made without departing from the spirit of the invention, as set forth by the claim.

It is also understood that the invention is not limited to any'specific use of the finished sulphurized oil. 1

Prior to this invention, compounds of the kind herein described have been employed in the rubber industry, as an aid in vulcanizing the rubber. However, the present invention does not relate to vulcanization, and the product derivedirom the invention is a sulphurized oil, free of constituents resembling rubber.

I claim:

In the art of sulphurizing fatty and mineral oils the process of avoiding thickening of the liquid oil which comprises heating a mixture of the liquid oil and sulphur in the presence of an aromatic amino compound selected from the group consisting of aniline, diphenyl guanidine, triphenyl guanidine, methylene-p-toluidine, diorthotolyl guanidine, ethylidene aniline, heptaldehyde aniline, formanilide, butylaldehyde aniline, and nitrosodimethylaniline, maintaining the 'oil at temperatures which retain it in a liquid condition durng the heating operation, limiting the temperature and time of said operation to positively prevent substantial thickening of the oil, and then completing the operation within said limits of temperature and time so as to convert the original liquid oil into a substantially non-thickened sulphurized liquid.

HARRY T. BENNETT.